diff options
| author | Hugh Dickins <hugh@veritas.com> | 2005-11-23 13:37:39 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-23 16:08:38 -0800 |
| commit | 01edcd891c3e9f4bb992ff2ceb69836bf76f8ddf (patch) | |
| tree | 3b8ab4808220d1caaf3ba34db16917f71b852a08 | |
| parent | cc3327e7dfc16a9a3e164075234c869867a59e45 (diff) | |
[PATCH] mm: powerpc ptlock comments
Update comments (only) on page_table_lock and mmap_sem in arch/powerpc.
Removed the comment on page_table_lock from hash_huge_page: since it's no
longer taking page_table_lock itself, it's irrelevant whether others are; but
how it is safe (even against huge file truncation?) I can't say.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/powerpc/mm/hugetlbpage.c | 4 | ||||
| -rw-r--r-- | arch/powerpc/mm/mem.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/mm/tlb_32.c | 6 | ||||
| -rw-r--r-- | arch/powerpc/mm/tlb_64.c | 4 |
4 files changed, 10 insertions, 6 deletions
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 426c269e552..9250f14be8e 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -754,9 +754,7 @@ repeat: } /* - * No need to use ldarx/stdcx here because all who - * might be updating the pte will hold the - * page_table_lock + * No need to use ldarx/stdcx here */ *ptep = __pte(new_pte & ~_PAGE_BUSY); diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 4bd7b0a7099..ed6ed2e30da 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -495,7 +495,7 @@ EXPORT_SYMBOL(flush_icache_user_range); * We use it to preload an HPTE into the hash table corresponding to * the updated linux PTE. * - * This must always be called with the mm->page_table_lock held + * This must always be called with the pte lock held. */ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte) diff --git a/arch/powerpc/mm/tlb_32.c b/arch/powerpc/mm/tlb_32.c index 6c3dc3c44c8..ad580f3742e 100644 --- a/arch/powerpc/mm/tlb_32.c +++ b/arch/powerpc/mm/tlb_32.c @@ -149,6 +149,12 @@ void flush_tlb_mm(struct mm_struct *mm) return; } + /* + * It is safe to go down the mm's list of vmas when called + * from dup_mmap, holding mmap_sem. It would also be safe from + * unmap_region or exit_mmap, but not from vmtruncate on SMP - + * but it seems dup_mmap is the only SMP case which gets here. + */ for (mp = mm->mmap; mp != NULL; mp = mp->vm_next) flush_range(mp->vm_mm, mp->vm_start, mp->vm_end); FINISH_FLUSH; diff --git a/arch/powerpc/mm/tlb_64.c b/arch/powerpc/mm/tlb_64.c index 53e31b834ac..859d29a0cac 100644 --- a/arch/powerpc/mm/tlb_64.c +++ b/arch/powerpc/mm/tlb_64.c @@ -95,7 +95,7 @@ static void pte_free_submit(struct pte_freelist_batch *batch) void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf) { - /* This is safe as we are holding page_table_lock */ + /* This is safe since tlb_gather_mmu has disabled preemption */ cpumask_t local_cpumask = cpumask_of_cpu(smp_processor_id()); struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur); @@ -206,7 +206,7 @@ void __flush_tlb_pending(struct ppc64_tlb_batch *batch) void pte_free_finish(void) { - /* This is safe as we are holding page_table_lock */ + /* This is safe since tlb_gather_mmu has disabled preemption */ struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur); if (*batchp == NULL) |